Greg, I would definitely consider contacting the guys running this eBay ad, tell them exactly what you want, and let them quote you a price.
Valley Springs Custom Differentials. Their eBay ad lists their phone number. I bought a 3.50 9" 28 spline posi third member from them last year via eBay and couldn't be happier. They gladly supplied the proper size pinion yoke for my application at no additional cost. When I looked around for price, I couldn't find any better. They are asking $500 for a third member with NEW gears, shipping included, now. I opted for a good used set of gears rather than new gears to try and save some cash and that dropped my price close to $100. My rear is completely quiet and was set up perfectly upon arrival. They ship the unit in a plastic 5 gallon pail and it arrived in perfect condition, painted and ready to pop in. Curry is excellent for quality but I bet their price will be significantly higher than these guys.